MEDICAL PHYSIOLOGY

Detailed explanation-1: -The left and right ventricles contact. This closes the mitral and tricuspid valves preventing back blood flow. At the same time, the aortic and pulmonic valves open to let blood be pumped out of the heart.

Detailed explanation-2: -We conclude that combined valve replacement and bypass surgery can be performed successfully, even in the patients at higher risk; however, this operation should be performed only by teams with demonstrated success in surgically treating advanced coronary artery disease.

Detailed explanation-3: -All Valves Closed When the intraventricular pressures fall sufficiently at the end of phase 4, the aortic and pulmonic valves abruptly close (aortic precedes pulmonic) causing the second heart sound (S2) and the beginning of isovolumetric relaxation.

Detailed explanation-4: -When the two atrium chambers contract, the tricuspid and mitral valves open, which both allow blood to move to the ventricles. When the two ventricle chambers contract, they force the tricuspid and mitral valves to close as the pulmonary and aortic valves open.